Question

Which of the following has filament with low melting point?
(A) Electric Bulb
(B) Fuse Wire
(C) Room Heater
(D) Electric Iron

Answer 1

Hint: When a filament has low melting point than filament starts melting on small increase in temperature of filament. When we pass electric current through the filament, its temperature is increased due to heat loss because of resistance of filament and filament melt on small increase in temperature and circuit breaks due to which flow of current stops in the circuit.

Complete step by step solution
Electric bulbs are used to provide light then it is simple that filament of electric bulbs should be stable at high means the melting point of filament is high.
Fuse wire used for safety purposes of electric appliances. Fuse wire protects appliances from unnecessary current or large amounts of current which can damage them, when large amounts of current flows through the circuit fuse wire break circuit due to melting of its filament. Similar to electric bulb room heaters and electric iron are used at high temperature, their filaments have a high melting point.

Hence, the correct answer is Fuse wire.

Note Always check that the melting point of the fuse wire is low enough that it melts on a large amount of current. As we know the requirements of current are different at different places, then filament of fuse wire is made up of different dimensions for different uses. To increase the range of current of the fuse wire simply increase its diameter to reduce resistance and energy loss.